Preheat the oven to 425 degrees.

Carefully cut the potatoes into 1/4″ thin matchsticks, or to your desired thickness and length.  Place potatoes a large bowl, and toss with the oil, salt, garlic powder, pepper and cayenne until the potatoes are evenly coated.  Spread out the potatoes out in a single layer on a parchment-covered baking sheet.  (If your baking sheet is small, you may need to use two.)

Cook for 15-20 minutes, flipping the fries once or twice during that time so that they cook evenly.  (Cooking times will vary based on the size and thickness of your fries.) Remove once the edges slightly begin to brown and fries begin to crisp.  Immediately sprinkle with Parmesan cheese and parsley, and toss briefly to combine.  Serve warm.